The present disclosure relates to the manufacture of a Neodymium-Iron-Boron (Nd—Fe—B) sintered magnet using Grain Boundary Engineering (GBE).
The global market for Rare Earth Permanent Magnets (REPM) is growing together with the range of REPM applications. REPM's exhibit high magnetic performance characteristics, and are used in the development of high-tech, high-efficiency applications in many industries including electronics, energy, transportation, aerospace, defense, medical devices, and information and communication technology.
For example, applications using the Nd—Fe—B permanent magnets include: starter motors, anti-lock braking systems (ABS), fuel-pumps, fans, loudspeakers, microphones, telephone ringers, switches, relays, hard-disk drives (HDD), stepper motors, servo-motors, magnetic resonance imaging (MRI), windmill generators, robotics, sensors, magnetic separators, guidance systems, satellites, cruise missiles, and so on.
The Nd—Fe—B type sintered magnet has a very fine tuned elemental composition, which includes, besides Nd, elements like Dy, Tb, Ga, Co, Cu, Al and other minor transitional metal elemental additions.
The use of heavy rare earth Dysprosium (Dy) may help to improve the temperature resistance of Nd—Fe—B magnets. Despite its performance-boosting characteristics, Dy resources are limited. Dy supply risk and scarcity cause a shortage of high temperature performance Nd—Fe—B magnets which can be used in energy-saving motor applications.
The present disclosure for Grain Boundary Engineering reduces the Dy content in the Nd—Fe—B product while maintaining high performance, increasing temperature resistance, and lowering production cost.